JPH01314064A - Solid-state image pickup device - Google Patents

Abstract

PURPOSE:To make the device small in size and to reduce the signal readout time by arranging photoelectric conversion element arrays detecting the primary color signal or its complementary color signal required to reproduce the color of each picture element in parallel for each color. CONSTITUTION:The device consists of photoelectric conversion arrays 5-7, charge transfer gates 9, 11, 13, charge transfer devices 8, 10, 12 and impedance conversion amplifiers 14-16. Then the photoelectric conversion element arrays 5-7 are arranged in parallel for each color of the primary color or its complementary color and the charge transfer devices 8, 10, 12 are provided also to the arrays 5-7 to read a signal charge and the charge transfer devices 8, 10, 12 for signal readout are provided together for the photoelectric conversion element arrays 5-7 to arrange linear image sensors in parallel for each hue. Thus, the device is made small in size and the transfer efficiency for signal readout is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a solid-state imaging device comprising a linear image sensor that detects optical image information, converts it into an electrical signal, and outputs it.

[Conventional technology]

Solid-state imaging devices consisting of linear image sensors have already been put into practical use in fields such as facsimiles, 0CRS1 cameras, and non-contact measuring instruments.

The structure of a conventional solid-state imaging device will be explained based on FIG. 4. It includes a photodiode-dimensional array 1 that converts the pattern of incident light into an electrical signal, and a scanning array that reads out the charges accumulated in each photodiode in time series. It consists of a linear image sensor equipped with a circuit 2. More specifically, in the case of a color image sensor, red (R), blue (B), and green (G) color filters are sequentially provided on the surface of a set of three photodiodes. The scanning circuit 2 consists of a charge transfer device (CCD) having a charge transfer element corresponding to each photodiode, -
After the charges accumulated in the respective photodiodes of the dimensional array 1 are transferred in parallel to respective predetermined charge transfer elements via the transfer gate 3, the charges are sequentially transferred in synchronization with a clock signal based on a so-called four-phase drive method. The signal is transferred in the longitudinal direction, converted into a low impedance signal by the source follower amplifier 4, and output as a time-series video signal.

[Problem to be solved by the invention]

However, in such conventional solid-state imaging devices, as shown in Figure 4, to reproduce the color of one pixel, a set of three photodiodes, R, G, and B, are arranged in a row. Since the number of pixels is increased in order to achieve higher resolution, the length of the photodiode dimensional array l in the longitudinal direction becomes extremely long, which increases the size of the device and requires a long time to read out all signals. This may lead to problems such as the need for

[Means to solve the problem]

The present invention has been made in view of these problems, and it is an object of the present invention to provide a solid-state imaging device having a structure that can reduce the size of the device and shorten the signal readout time.

In order to achieve this object, the present invention arranges photoelectric conversion element arrays in parallel for each of the primary colors or complementary colors necessary for reproducing the colors of individual pixels for detecting the primary colors or their complementary colors, By providing a charge transfer device for signal readout in each photoelectric conversion element array, so-called linear image sensors were arranged in parallel for each hue.

[Effect]

In the solid-state imaging device of the present invention having such a configuration, the photoelectric conversion element array that detects the color signal of the primary color or complementary color necessary for color reproduction of each pixel is arranged in parallel for each color, which is different from the conventional one. It does not become long in the column direction. As a result, it is possible to prevent the device from increasing in size and improve the transfer efficiency for signal reading.

〔Example〕

An embodiment of the solid-state imaging device according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the first embodiment, and in the same figure, 5 is a color filter for detecting one of the three primary colors or their complementary colors, such as red (R), for reproducing colors. 6 is a photoelectric conversion element array consisting of a group of photodiodes provided with a color filter for detecting other colors, such as blue (B); 7 is a photoelectric conversion element array consisting of a group of photodiodes provided with a color filter for detecting other colors such as blue (B); and 7 is the remaining photoelectric conversion element array. This is a photoelectric conversion element array consisting of a group of photodiodes provided with a color filter for detecting a color such as green (G), and each photodiode in each array is aligned at the same pitch. Arranged in columns.

Reference numeral 8 denotes a charge transfer device having a charge transfer element corresponding to each photodiode of the first photoelectric conversion element array 5. It is provided. 10
is a charge transfer device having a charge transfer element corresponding to each photodiode of the second photoelectric conversion element array 6, and is provided in parallel with the second photoelectric conversion element array 6 via a charge transfer gate 11 attached to the photoelectric conversion element array 6. It is being Reference numeral 12 denotes a charge transfer device having a charge transfer element corresponding to each photodiode of the third photoelectric conversion element array 7, and the charge transfer device 12 has charge transfer elements corresponding to each photodiode of the third photoelectric conversion element array 7. It is provided. 1st.
Second. The impedance conversion amplifier 1 is connected to the charge transfer element at the end of each third charge transfer device 8.10.11.
4.15.16 are formed. Note that this sensor is integrally formed on the same semiconductor chip.

Next, the operation of such a solid-state imaging device will be explained.

When the solid-state imaging device is applied to a facsimile machine, a copier, etc., it is moved in the direction of arrow X relative to a copy document, etc. Then, a signal reading operation, which will be described later, is performed every time it is moved at a predetermined pitch. That is, in the signal reading operation, optical image information from a copy document or the like is transferred to the first to third photoelectric conversion element arrays 5. 6. After photoelectric conversion is performed by each photodiode 7 and signal charge is accumulated for a predetermined period, the charge transfer device 9.11.13 is made conductive and the signal charge of the photodiode is transferred to the charge transfer device 8, 10.12. to the corresponding charge transfer element. Next, for example, four-phase drive signals of the same timing are applied to the charge transfer devices 8 and 1.
By applying a voltage of 0.12 to the transfer gate electrode (not shown), a time-series image signal is output from the impedance conversion amplifiers 14, 15, and 16 for each charge transfer element arranged in the row direction in FIG. do.

According to this embodiment, photoelectric conversion element arrays are arranged in parallel for each hue of the primary color or its complementary color, and a charge transfer device is attached to these arrays to read signal charges. It does not become a long and large image sensor, and can be made more compact. Further, since the signal charges for each hue are read out in parallel through the plurality of charge transfer devices, the readout speed can be increased. Furthermore, since the image signals of each hue can be output in parallel in synchronization with the drive signal for charge transfer, it is suitable for signal processing such as image reproduction.

Next, a second embodiment will be described based on FIG.

In the figure, 17 is a first photoelectric conversion element array having a photodiode group provided with a color filter that detects one of the primary colors or its complementary color, for example, red (R), and 18 is any other photoelectric conversion element array. A second photoelectric conversion element array 19 has a photodiode group provided with a color filter for detecting one hue, for example, blue (B), and 19 is a photoelectric conversion element array provided with a color filter for detecting the remaining hue, for example, green (B). - A third photoelectric conversion element array having a group of diodes. A charge transfer device 20 is formed in parallel with the first photoelectric conversion element array 17 through a charge transfer gate 21, and has a charge transfer element corresponding to each photodiode. Furthermore, an impedance conversion amplifier 22 is formed in the charge transfer element at the final end, and when the charge transfer gate 21 is turned on, the first
Only the signal charges generated in the odd-numbered photodiodes of the photoelectric conversion element array 17 are transferred to the corresponding charge transfer elements.

A charge transfer device 23 is formed in parallel with a charge transfer gate 24 provided on the opposite side of the charge transfer gate 210, and has a charge transfer element corresponding to each photodiode. Furthermore, an impedance conversion amplifier 25 is formed in the charge transfer element at the final end, and when the charge transfer gate 24 is turned on, only the signal charges generated in the even-numbered photodiodes of the first photoelectric conversion element array 17 are transferred. to the corresponding charge transfer element. Note that the charge transfer gates 21 and 24 are connected in common at one end, and are controlled to be conductive or non-conductive by a control signal for gate opening at the same timing.

On both sides of the second photoelectric conversion element array 18, charge transfer gates 26, 27 similar to those of the first photoelectric conversion element array 17,
Charge transfer devices 28, 29 and impedance conversion amplifiers 30, 31 are formed. That is, the charge transfer device 28 is formed in parallel through the charge transfer gate 26 provided alongside the second photoelectric conversion element array 18, and has a charge transfer element corresponding to each photodiode.
An impedance conversion amplifier 30 is formed in the charge transfer element at the final end, and when the charge transfer gate 26 is turned on, only the signal charge generated in the odd-numbered photodiode of the second photoelectric conversion element array 18 is transferred to the corresponding one. The charge transfer element is configured to transfer the charge to the charge transfer element.

Further, a charge transfer gate 2 is provided on the opposite side of the charge transfer gate 260.
7 via charge transfer device 29. are formed in parallel,
It has a charge transfer element corresponding to each photodiode, and an impedance conversion amplifier 31 is formed in the charge transfer element at the final end, and when the charge transfer gate 27 is turned on, the charge transfer element at the even numbered position of the second photoelectric conversion element array 18 is connected. Only the signal charge generated in the photodiode is transferred to the corresponding charge transfer element. Note that the charge transfer gates 26 and 27 are connected in common at one end, and are controlled to be conductive or non-conductive by a control signal for gate opening at the same timing.

Furthermore, charge transfer gates similar to those of the first photoelectric conversion element array 17 are provided on both sides of the third photoelectric conversion element array 19).
3. Charge transfer devices 34 and 35 and impedance conversion amplifiers 36 and 37 are formed. That is, the charge transfer gate 3 attached to the third photoelectric conversion element array 19
A charge transfer device 34 is formed in parallel through the photodiodes 2 and has a charge transfer element corresponding to each photodiode, and an impedance conversion amplifier 36 is formed in the charge transfer element at the final end, and the charge transfer gate 32 is turned on. Then, only the signal charges generated in the odd-numbered photodiodes of the third photoelectric conversion element array 19 are transferred to the corresponding charge transfer elements. Further, on the opposite side of the charge transfer gate 32, a charge transfer device 35 is formed in parallel via a charge transfer gate 33, and has a charge transfer element corresponding to each photodiode, and has an impedance at the endmost charge transfer element. A conversion amplifier 37 is formed so that when the charge transfer gate 33 becomes conductive, only the signal charge generated in the even-numbered photodiode of the third photoelectric conversion element array 19 is transferred to the corresponding charge transfer element. It has become.

Incidentally, charge transfer gates 32 and 33 are connected in common at one end, and conduction/non-conduction is controlled by a control signal for gate opening at the same timing.

Next, the operation of the second embodiment will be explained. When this solid-state imaging device is applied to a facsimile machine, a copier, etc., it is moved relative to a copy document, etc. in the direction of arrow X. Then, a signal reading operation, which will be described later, is performed every time it is moved at a predetermined pitch.

That is, in the signal reading operation, optical image information from a copy document or the like is transferred to the first to third photoelectric conversion element arrays 17, 18, .
After photoelectric conversion is performed by each of the photodiodes 19 and signal charges are accumulated for a predetermined period, the charge transfer gate 21 .
24°26, 27.32.33 are made conductive and the signal charge of the photodiode is transferred to the charge transfer device 20.23.2
8.29.34.35 to the corresponding charge transfer element. Charge transfer device 20.23.28.2
9, 34, and 35 are made conductive at the same time by the same control signal. Next, by applying, for example, four-phase drive signals at the same timing to the transfer gate electrodes (not shown) of the charge transfer devices 20, 23.2B, 29.34.35, the first
Impedance conversion amplifier 22, 25, 30, 31, 36, 37 for each charge transfer element arranged in the row direction of the figure.
Outputs time-series image signals from. Here, the impedance conversion amplifier 22.30.36 outputs the signal from the odd-numbered photodiode, and the impedance conversion amplifier 25.31.3'7 outputs the signal from the even-numbered photodiode. The respective outputs are alternately output in synchronization with the drive signal. Then, by chronologically combining the output signals in synchronization with this output timing, the signals from all the photodiodes can be reproduced.

According to this embodiment, the charge transfer efficiency in signal readout can be further improved compared to the first embodiment.

Next, a third embodiment will be described based on FIG.

This embodiment is a modification of the solid-state imaging device shown in FIG. 2, and the same or corresponding parts as in FIG. 2 are designated by the same reference numerals. To explain the difference from FIG. 2, the charge transfer device 2 provided corresponding to the first photoelectric conversion element array 17
A charge transfer element is formed to connect the charge transfer element at the end of 0.23 to a common charge transfer element 38, and an impedance conversion amplifier 39 is further connected to the charge transfer element 38. Further, a charge transfer element is formed for connecting the charge transfer elements at the ends of the charge transfer devices 28 and 29 provided corresponding to the second photoelectric conversion element array 18 to the common charge transfer element 40, and further, The charge transfer element 40
An impedance conversion amplifier 41 is connected to.

Furthermore, a charge transfer element is formed for connecting the charge transfer elements at the ends of the charge transfer devices 34 and 35 provided corresponding to the third photoelectric conversion element array 19 to the common charge transfer element 42, and further, An impedance conversion amplifier 43 is connected to the charge transfer element 42 .

When such a configuration is used and the same control as in the second embodiment shown in FIG. 2 is performed, signals related to each hue are outputted via the respective impedance conversion amplifiers 39, 41, and 43. According to this embodiment, each photoelectric conversion element array 17.1
Since the signals from the odd-numbered and even-numbered photodiodes of 8.19 are automatically and alternately outputted in time series, signal processing can be facilitated.

〔Effect of the invention〕

As explained above, according to the solid-state imaging device of the present invention, each linear sensor detects the hue of a primary color or complementary color necessary for color reproduction.
Since the image sensors are arranged in parallel for each hue, the overall structure of the device can be miniaturized, optical registration is easy, the signals of each hue can be read out synchronously, and the signal This has effects such as being able to improve signal transfer efficiency for reading.

[Brief explanation of the drawing]

FIG. 1 is a block diagram symbolically showing the configuration of one embodiment of the present invention, FIG. 2 is a block diagram symbolically showing the configuration of another embodiment, and FIG. 3 is a block diagram symbolically showing the configuration of another embodiment. FIG. 4 is a block diagram showing the configuration of a conventional solid-state imaging device. 5, 6. 7.1? , 18.19; photoelectric conversion element array 9, . 11.13.21, 24.26, 27.3
2.33; Charge transfer gate 8, 10.12.20.
23, 28, 29, 34, 35 ; Charge transfer device 14. 15, 16, 22, 25, 30. 31, 36, 3
7, 39, 41.4'3; Impedance conversion amplifier 38, 40.42; Charge transfer element agent (81
07) Patent attorney Kiyotaka Sasaki (and 3 others) Ward 1

Claims (1)

[Claims] A solid-state imaging device characterized in that linear image sensors that detect the hues of primary colors or complementary colors necessary for color reproduction are arranged in parallel for each hue.